Before I run to the store and buy a whole kit and/or have to wait until I have access to a tap and die set, does anyone know what thread the typical overflow drain trim screw thread is?

I'm looking at something like this

https://www.plumbingsupply.com/drain...overflowplates

01002 (plate)
01024 (screw)
11641 (adapter bar)

What is installed is identical in appearance to the parts shown in the link above with the exception of the lack of the wording "WATCO" (it even has the stamped "CLEANOUT" on the overflow plate.)

basically, I need to remove this and re-gasket it as someone took a big deep bath where the water hit the overflow and caused a leak. However when attempting to remove the plate, the screw is completely destroyed - once I backed it out a little bit the diameter is so completely destroyed by rust that it won't screw out any more so will need to be cut.

I was going to replace it with either a chrome plated brass (if I can find one) or stainless steel screw to allow more easy serviceability in the future, but need to have the new screw on hand so as not to leave an exposed overflow while sourcing same which will likely cause issues with the design department.

I'm assuming that this is a standard thread - maybe 10-24? - but don't know what it is not being a plumber.

I'm hoping that HD or Lowe's will have the screw but I'm not counting on it, probably going to have to order from McMaster...

thanks

Nate